Pregnant women feel chest tightness and shortness of breath when they are more than six months pregnant, most of them are due to the gradually increasing uterus pressing on the diaphragm, the diaphragm uplift will affect the breathing, but also increase the blood volume, aggravate the burden of the heart, cause chest tightness and shortness of breath phenomenon. Symptoms are not very serious, you need to pay attention to rest, avoid overwork, breathe fresh air, and oxygen if necessary, most of them can be relieved. However, if the symptoms are more serious, it is considered to be caused by respiratory diseases and heart diseases, such as colds, bronchitis, congenital heart disease, myocardial ischemia, high blood pressure, which may cause, you need to go to the hospital to do the appropriate examination to make a clear diagnosis, and actively under the guidance of the doctor’s treatment.